title: Immune cell-mediated inflammation and the early improvements in glucose metabolism after gastric banding surgery.
abstract: OBJECTIVE
  The contribution of immune cells to the inflammasome that characterises type 2 diabetes mellitus and obesity is under intense research scrutiny. We hypothesised that early changes in glucose metabolism following gastric banding surgery may relate to systemic inflammation, particularly cell-mediated immunity.
  
  
  METHODS
  Obese participants (BMI 43.4 ± 4.9 kg/m(2), n = 15) with diabetes or impaired glucose tolerance (IGT) underwent laparoscopic adjustable gastric banding surgery. Measurements taken before, and at 2 and 12 weeks after surgery included: fasting glucose, glucose levels 2 h after a 75 g oral load, glucose incremental AUC, oral glucose insulin sensitivity index (OGIS), circulating immune cell numbers and activation, and adipokine levels. Subcutaneous and visceral adipose tissue were collected at surgery, and macrophage number and activation measured.
  
  
  RESULTS
  There were significant reductions in fasting and 2 h glucose, as well as improved OGIS at 2 and 12 weeks. At 12 weeks, 80% of the diabetic participants reverted to normal glucose tolerance or IGT, and all IGT participants had normalised glucose tolerance. The 12 week fall in fasting glucose was significantly related to baseline lymphocyte and T lymphocyte numbers, and to granulocyte activation, but also to the magnitude of the 12 week reduction in lymphocyte and T lymphocyte numbers and TNF-α levels. In a model that explained 75% of the variance in the change in fasting glucose, the 12 week change in T lymphocytes was independently associated with the 12 week fall in fasting glucose.
  
  
  CONCLUSIONS
  Rapid improvements in glucose metabolism after gastric banding surgery are related to reductions in circulating pro-inflammatory immune cells, specifically T lymphocytes. The contribution of immune cell-mediated inflammation to glucose homeostasis in type 2 diabetes and its improvement after bariatric surgery require further investigation.
authors.affiliation: Diabetes and Obesity Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia, k.samaras@garvan.org.au.
authors.forename: Katherine
authors.initials: K
authors.lastname: Samaras
authors.forename: Alexander
authors.initials: A
authors.lastname: Viardot
authors.forename: Natalia K
authors.initials: NK
authors.lastname: Botelho
authors.forename: Alicia
authors.initials: A
authors.lastname: Jenkins
authors.forename: Reginald V
authors.initials: RV
authors.lastname: Lord
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology; D054392:Adipokines / Q000378:metabolism; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D005260:Female; D015391:Gastroplasty; D018149:Glucose Intolerance; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000503:physiopathology; D010535:Laparoscopy; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000276:immunology / Q000503:physiopathology / Q000601:surgery*; D012074:Remission Induction; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D054392:Adipokines; D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D014409:Tumor Necrosis Factor-alpha; C517652:hemoglobin A1c protein, human